These include (1) vesicular transporters that localize to synaptic vesicles, actively driving transmitter into the vesicular lumen and (2) plasma membrane transporters that terminate neurotransmission by the uptake of neurotransmitter into either the presynaptic GSI-IX ic50 site of release or adjacent cells. The number of known vesicular transporters is surprisingly small and includes four distinct families for the transport of the following: (1) monoamines, such as dopamine and serotonin (VMAT1 and VMAT2); (2) GABA and glycine (VGAT or VIAAT); (3)

acetylcholine (VAChT); and (4) glutamate (VGLUT1-3; Chaudhry et al., 2008). Additional transporters for purine nucleotides (Sawada et al., 2008) and aspartate (Miyaji selleck screening library et al., 2008) have recently been identified as part of the SLC17 family, related to VGLUTs. Any other novel neurotransmitters

used by invertebrates and/or mammals would similarly require a distinct vesicular transporter for storage and exocytotic release. In Drosophila and other insects, the mushroom bodies (MBs) play a critical role in olfactory learning, as well as integrating information from other sensory modalities ( Davis, 2011, Keene and Waddell, 2007, Strausfeld et al., 1998 and Wessnitzer and Webb, 2006). Kenyon cells (KCs) form all of the intrinsic fiber tracts of the MBs, whereas several extrinsic neurons project into the MBs, providing input and output of information and/or regulating KC function ( Tanaka et al., 2008). To date, neither the neurotransmitter released from the intrinsic neurons nor the vesicular transporter responsible for

its storage has been identified. Of the known neurotransmitter systems, the vesicular transporters for amines (DVMAT), GABA (DVGAT), and glutamate (DVGLUT) are absent from KCs ( Chang et al., 2006, Daniels et al., 2008 and Fei et al., 2010). Although Farnesyltransferase expression data for the vesicular acetylcholine transporter is not available, the biosynthetic enzyme responsible for Ach synthesis is also absent from KCs ( Gorczyca and Hall, 1987 and Yasuyama et al., 2002). Several classical and peptide neurotransmitters have been identified in processes that project into the MBs ( Davis, 2011). In contrast, although multiple candidates have been suggested ( Schäfer et al., 1988, Schürmann, 2000 and Sinakevitch et al., 2001), the neurotransmitter released from the KCs is not known and could possibly constitute a previously undescribed neurotransmitter system. The MBs have been implicated in other behaviors, including sleep (Joiner et al., 2006), aggression (Baier et al., 2002), and motor activity (Serway et al., 2009). Furthermore, both the MBs and the central complex (CCX) have been linked to aspects of sexual behavior (O’Dell et al., 1995, Popov et al., 2003 and Sakai and Kitamoto, 2006).